Composite rocker shaft with integrated oil galleries

ABSTRACT

A rocker shaft for oiling engine components includes an outer tube and an insert extending through the outer tube. The insert defines a plurality of lumens. Each of the plurality of lumens extends through the insert and is configured to receive oil from an oil pump. An engine system includes a cylinder block, a cylinder head connected to the cylinder block, an overhead structure connected to the cylinder head, and a rocker shaft connected to the overhead structure such that a first end of a rocker arm connected to the rocker shaft is positioned above a cylinder of the cylinder block. A method of manufacturing the rocker shaft includes providing an outer tube and an insert, placing the insert in the outer tube, and aligning each of a plurality of lumens defined by the insert with a plurality of outer oil holes defined by the outer tube.

TECHNICAL FIELD

The present disclosure relates generally to rocker shafts for use ininternal combustion engine systems.

BACKGROUND

For an engine system, it may be desirable to provide lubrication ofengine components by providing oil to a rocker shaft. One approach thatcan be implemented to provide oil lubrication using a rocker shaft is todrill lumens into the rocker shaft. However, in a long rocker shaft,drilling multiple, narrow lumens into the rocker shaft can be expensiveand difficult to manufacture. In addition, rocker shafts have generallynot been able to be manufactured with lumens that extend the full lengthof the rocker shaft.

SUMMARY

According to a first set of embodiments, a rocker shaft comprises anouter tube and an insert extending through the outer tube. The insertdefines a plurality of lumens therein, each of the plurality of lumensextending through the insert. Each of the plurality of lumens areconfigured to receive oil from an oil pump.

According to a second set of embodiments, an engine system comprises acylinder block, a cylinder head connected to the cylinder block, and anoverhead structure connected to the cylinder head such that the cylinderhead is positioned between the cylinder block and the overheadstructure. The engine system further includes a rocker shaft connectedto the overhead structure such that a first end of a rocker armconnected to the rocker shaft is positioned above a cylinder of thecylinder block. The rocker shaft includes an outer tube and an insertextending through the outer tube. The insert defines a plurality oflumens therein. Each of the plurality of lumens extend through theinsert. Each of the plurality of lumens are configured to receive oilfrom an oil pump.

According to a third set of embodiments, a method of manufacturing arocker shaft for oiling engine components comprises providing an outertube and an insert. The method further includes placing the insert inthe outer tube and aligning each of a plurality of lumens defined by theinsert, and extending through the insert, with a plurality of outer oilholes formed in the outer tube.

This summary is illustrative only and is not intended to be in any waylimiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will become more fully understood from the followingdetailed description, taken in conjunction with the accompanyingfigures, wherein like reference numerals refer to like elements, inwhich:

FIG. 1 is a cross-sectional view of an engine system according to oneembodiment, showing a position of a rocker shaft.

FIG. 2 is a perspective view of an overhead structure of the enginesystem of FIG. 1 , showing a position of the rocker shaft of FIG. 1 .

FIG. 3 is a perspective view of the rocker shaft of FIG. 1 .

FIG. 4 is a transparent, perspective view of the rocker shaft of FIG. 1.

FIG. 5 is a flowchart of a method of manufacturing a rocker shaft foroiling engine components, according to an embodiment.

The foregoing and other features of the present disclosure will becomeapparent from the following description and appended claims, taken inconjunction with the accompanying drawings. Understanding that thesedrawings depict only several embodiments in accordance with thedisclosure and are therefore, not to be considered limiting of itsscope, the disclosure will be described with additional specificity anddetail through use of the accompanying drawings.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thedetailed description, drawings, and claims are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented here. It will be readily understood that the aspects of thepresent disclosure, as generally described herein, and illustrated inthe figures, can be arranged, substituted, combined, and designed in awide variety of different configurations, all of which are explicitlycontemplated and made part of this disclosure.

Implementations herein relate to a rocker shaft that includes an insertextending through an outer tube of the rocker shaft and a plurality oflumens extending through the outer tube of the rocker shaft. The insertmay be, for example, extruded, injection molded, sintered, die cast,investment cast, or additively manufactured. The plurality of lumens areconfigured to receive oil from an oil pump and to allow oil to exit fromthe rocker shaft through a plurality of outer oil holes formed in theouter tube. In this way, the rocker shaft may provide benefits such asallowing for different configurations of lumens in rocker shafts foroiling engine components, allowing for multiple separate passageways foroil within a single rocker shaft, allowing for simplified manufacturewithout drilling of the rocker shaft, and allowing for lumens thatextend through the full length of the rocker shaft.

FIG. 1 depicts an engine system 100, according to an example embodiment.The engine system 100 may be a diesel powered engine system 100, aspark-ignition engine system powered by gasoline, ethanol, or other fuelemployed by spark-ignition engine systems, or other type of enginesystem. The engine system 100 may be on a passenger vehicle (e.g.,sedan, van, pick-up truck, etc.), a commercial vehicle (e.g.,semi-trailer truck, etc.), or on another system that employs an enginesystem 100 including stationary systems.

The engine system 100 includes a cylinder block 110 (e.g., enginecomponent, block, etc.). The cylinder block 110 includes a plurality ofcylinders 112 positioned within the cylinder block 110. The cylinders112 are configured to allow a plurality of pistons 114 to move withinthe cylinders 112. Each cylinder 112 may be configured to allow one ortwo pistons 114 to move within the cylinder 112. The cylinder block 110may have one, two, three, four, five, six, or more cylinders 112. Thecylinders 112 may be positioned in a single row or in multiple rows.

A cylinder head 120 (e.g., engine component, head, etc.) is connected tothe cylinder block 110. The cylinder head 120 is configured to providecombustion chambers 121 that align with the cylinders 112 of thecylinder block 110. A channel 126 is formed in the cylinder head 120 toallow intake gases and exhaust gases to enter and exit the cylinder 112and the combustion chamber 121 when the engine system 100 is operated.

FIG. 2 depicts an overhead structure 130 (e.g., engine component, etc.)that is connected to the cylinder head 120 such that the cylinder head120 is positioned between the cylinder block 110 and the overheadstructure 130, as shown in FIG. 1 . In alternative arrangements, theoverhead structure 130 is connected to the cylinder head 120 such thatthe cylinder head 120 is not positioned between the cylinder block 110and the overhead structure 130.

A camshaft 138 (e.g., engine component, etc.) may be connected to theoverhead structure 130. The camshaft 138 may have a plurality of camlobes 139 positioned along the length of the camshaft 138.

As shown in FIGS. 1-2 , a rocker shaft 200 (discussed in further detailherein) is connected to the overhead structure 130 using a fastener 132(e.g., bolt, screw, etc.). In alternative arrangements, the rocker shaft200 may be attached to another engine component of the engine system 100and/or may be attached by other techniques. In some embodiments and asshown in FIGS. 1-2 , the engine system 100 has one rocker shaft 200. Inalternative arrangements, the engine system 100 may have one, two,three, four, or more rocker shafts 200.

As shown in FIGS. 1-2 , a plurality of rocker arms 134 (e.g., enginecomponents, etc.) is attached to the rocker shaft 200. In someembodiments and as shown in FIGS. 1-2 , at least two rocker arms 134 areattached to the rocker shaft 200 for each cylinder 112 of the cylinderblock 110. In alternative arrangements, at least one rocker arm 134 maybe attached to the rocker shaft 200 for each cylinder 112 of thecylinder block 110.

Each of the plurality of rocker arms 134 has a first end 135 that ispositioned above a cylinder 112 of the cylinder block 110. The first end135 of each of the plurality of rocker arms 134 is connected to a valvestem 124 that is connected to a valve head 122 that is positioned abovethe cylinder 112.

Each of the plurality of rocker arms 134 has a second end 136. In someembodiments and as shown in FIG. 2 , the second end 136 of each of theplurality of rocker arms 134 has a cam follower 137. The cam follower137 is positioned such that when the camshaft 138 rotates, the cam lobe139 of the camshaft 138 contacts the cam follower 137 and moves thesecond end 136 of the respective rocker arm 134. In alternativearrangements, a pushrod may be positioned between the cam lobe 139 ofthe camshaft 138 and the second end 136 of each of the plurality ofrocker arms 134 such that the cam lobe 139 moves the pushrod, whichmoves the second end 136 of the respective rocker arm 134. Moving thesecond end 136 of each of the plurality of rocker arms 134 also movesthe first end 135 of the respective rocker arm 134 so that the valvestem 124 moves the valve head 122, opening and closing the cylinder 112to the channel 126 of the cylinder head 120.

FIG. 3 depicts a perspective view of a rocker shaft 200. FIG. 4 depictsa transparent, perspective view of the rocker shaft 200. The rockershaft 200 may be used in the engine system 100 of FIG. 1 . In someembodiments and as shown in FIGS. 1-2 , the rocker shaft 200 is attachedto the overhead structure 130. In alternative arrangements, the rockershaft 200 may be attached to another engine component.

The rocker shaft 200 includes an outer tube 202 (e.g., shaft, pipe,duct, cylinder, etc.). In some embodiments and as shown in FIGS. 1-4 ,the outer tube 202 has a circular cross-sectional shape. In alternativearrangements, the outer tube 202 may have a cross-sectional shape thatis a circle, a circular segment, a circular sector, an oval, a polygon,rounded polygon, or other geometric shape. In some exampleimplementations, the outer tube 202 may have a cross-sectional width(e.g., a diameter where the cross-sectional shape is circular) that isapproximately in a range of 1-10 cm. As used herein, a range of X to Yincludes X, Y, and values between X and Y. The outer tube 202 may have alength that is approximately equal to the length of the overheadstructure 130 or the engine system 100. In some example implementations,the outer tube 202 may have a length that is approximately in a range of5-300 cm. In some example implementations, the wall of the outer tube202 may have a width that is approximately in a range of 0.5-5 mm. Insome example implementations, the outer tube 202 comprises steel, whichallows for withstanding the loads place on the outer tube 202 by theoperation of the engine system 100.

An insert 204 (e.g., core, interior, etc.) extends through the outertube 202. An outer surface of the insert 204 contacts the inner surfaceof the outer tube 202. The insert 204 may have a length that is equal toor greater than the length of the outer tube 202. The insert 204 mayhave a cross-sectional shape that is a circle, a circular segment, acircular sector, an oval, a polygon, rounded polygon, or other geometricshape. In some example implementations, the insert 204 may have across-sectional width (e.g., a diameter where the cross-sectional shapeis circular) that is approximately in a range of 0.5-9.5 cm.

In some example implementations, the insert 204 may comprise a materialselected from the group consisting of aluminum, steel, ceramic, apolyamide, a polymer, and a polymer composite. Other materials may beused as well. In some example implementations, the insert 204 may bemanufactured by extrusion, by injection molding, by sintering, by diecast, by investment cast, by additive manufacturing, or by othermanufacturing techniques. In some example implementations, the insert204 may comprise sintered steel, sintered ceramic, an injection moldedpolyamide, an injection molded polymer, an injection molded polymercomposite, an extruded polyamide, an extruded polymer, an extrudedpolymer composite, extruded aluminum, or die cast aluminum.

In some embodiments and as shown in FIGS. 3-4 , the outer tube 202defines an outer recessed groove 212 (e.g., cut, furrow, indentation,etc.) formed therein and the insert 204 defines an inner recessed groove213 (e.g., cut, furrow, indentation, etc.) formed therein. Inalternative arrangements, the outer tube 202 does not have an outerrecessed groove 212 and/or the insert 204 does not have an innerrecessed groove 213. In alternative arrangements, the outer tube 202 mayhave one, two, three, four, five, six, seven or more outer recessedgrooves 212, and/or the insert 204 may have one, two, three, four, five,six, seven or more inner recessed grooves 213. The outer recessed groove212 and the inner recessed groove 213 allow the rocker shaft 200 to beattached to an engine component of the engine system 100 such as theoverhead structure 130. In some embodiments and as shown in FIGS. 3-4 ,the outer recessed groove 212 and the inner recessed groove 213 eachhave a cross-sectional shape that is a circular segment. In alternativearrangements, the outer recessed groove 212 and/or the inner recessedgroove 213 may each have a cross-sectional shape that is a circularsegment, a circular sector, a polygon, rounded polygon, or othergeometric shape. In some embodiments, each of the outer recessed grooves212 has the same cross-sectional shape and each of the inner recessedgrooves 213 has the same cross-sectional shape. In other embodiments, atleast one of the outer recessed grooves 212 may have a cross-sectionalshape that is different from that of another of the outer recessedgrooves 212, and/or at least one of the inner recessed grooves 213 mayhave a cross-sectional shape that is different from that of another ofthe inner recessed grooves 213.

The insert 204 defines a plurality of lumens 206, 208, and 210 (e.g.,galleries, channels, cavity, space, etc.). Each of the plurality oflumens 206, 208, and 210 extends through the insert 204. In someembodiments, at least one of the plurality of lumens 206, 208, and 210is formed between the outer tube 202 and the insert 204. In otherembodiments, at least one of the plurality of lumens 206, 208, and 210is formed in the insert 204. In some embodiments and as shown in FIGS.1-4 , the first lumen 206 is formed in the insert 204 and the secondlumen 208 and third lumen 210 are formed between the outer tube 202 andthe insert 204.

Each of the plurality of lumens 206, 208, and 210 is configured toreceive oil from an oil pump (not shown). In some embodiments, each ofthe plurality of lumens 206, 208, and 210 is configured to receive thesame oil from the same oil pump. In other embodiments, at least one ofthe plurality of lumens 206, 208, and 210 is configured to receive adifferent oil from a different oil pump than is another of the pluralityof lumens 206, 208, and 210.

In some embodiments and as shown in FIGS. 1-4 , the plurality of lumens206, 208, and 210 of the rocker shaft 200 includes three lumens 206,208, and 210. In alternative arrangements, the plurality of lumens 206,208, and 210 may include one, two, three, four, or more lumens.

Each of the plurality of lumens 206, 208, and 210 may have a length thatis equal to the length of the outer tube 202. When the insert 204 ismanufactured using injection molding, sintering, die cast, investmentcast, or additive manufacturing techniques, at least one of theplurality of lumens 206, 208, and 210 may have a length that is lessthan the length of the outer tube 202.

The plurality of lumens 206, 208, and 210 may have a cross-sectionalshape that is a circle, a circular segment, a circular sector, an oval,a polygon, rounded polygon, or other geometric shape. At least one ofthe plurality of lumens 206, 208, and 210 may have a cross-sectionalshape that is different from that of another of the plurality of lumens206, 208, and 210. In some embodiments and as shown in FIGS. 1-4 , thefirst lumen 206 has a cross-sectional shape that is a circle, the secondlumen 208 has a cross-sectional shape that is approximately a roundedpentagon, and the third lumen 210 has a cross-sectional shape that isapproximately a rounded triangle. When the insert 204 is manufacturedusing injection molding, sintering, die cast, investment cast, oradditive manufacturing techniques, at least one of the plurality oflumens 206, 208, and 210 may have a cross-sectional shape that variesover the length of the at least one of the plurality of lumens 206, 208,and 210.

In some example implementations, each of the plurality of lumens 206,208, and 210 may have a cross-sectional width (e.g., a diameter wherethe cross-sectional shape is circular) that is approximately in a rangeof 2-20 mm. At least one of the plurality of lumens 206, 208, and 210may have a cross-sectional width that is different from that of anotherof the plurality of lumens 206, 208, and 210. When the insert 204 ismanufactured using injection molding, sintering, die cast, investmentcast, or additive manufacturing techniques, at least one of theplurality of lumens 206, 208, and 210 may have a cross-sectional widththat varies over the length of the at least one of the plurality oflumens 206, 208, and 210.

In some embodiments and as shown in FIGS. 1-4 , the plurality of lumens206. 208, and 210 are positioned in the rocker shaft 200 so that thefirst lumen 206 is located to the left of the second lumen 208 and thethird lumen 210 is located to the right of the second lumen 208. Inalternative arrangements, the plurality of lumens 206, 208, and 210 maybe positioned at other locations of the rocker shaft 200 and withdifferent relative positioning to each other, as compared to thearrangement of the plurality of lumens 206, 208, and 210 of FIGS. 1-4 .

In some embodiments and as shown in FIGS. 3-4 , each of the plurality oflumens 206, 208, and 210 defines a straight pathway in the rocker shaft200. In alternative arrangements and when the insert 204 is manufacturedusing injection molding, sintering, die cast, investment cast, oradditive manufacturing techniques, at least one of the plurality oflumens 206, 208, and 210 may define a pathway that has bends. When atleast one of the plurality of lumens 206, 208, and 210 defines a pathwaythat has bends, the pathway of at least one of the plurality of lumens206, 208, and 210 may be positioned so that the at least one of theplurality of lumens 206, 208, and 210 is routed around an inner fastenerhole 215 of the rocker shaft 200 or around another feature of the rockershaft 200. When at least one of the plurality of lumens 206, 208, and210 defines a pathway that has bends, the pathway of the at least one ofthe plurality of lumens 206, 208, and 210 may have one, two, three,four, or more bends. In some example implementations, when at least oneof the plurality of lumens 206, 208, and 210 defines a pathway that hasbends, each of the bends may have an angle that is in a range of 0-180degrees. When at least one of the plurality of lumens 206, 208, and 210defines a pathway that has bends, each of the bends may be formed ascorners or as rounded segments. When at least one of the plurality oflumens 206, 208, and 210 defines a pathway that has bends, each of thebends may be formed in any radial direction of the rocker shaft 200.

The outer tube 202 defines a plurality of outer oil holes 216, 218, and220 (e.g., opening, gap, etc.) formed therein. The plurality of outeroil holes 216, 218, and 220 are connected to the plurality of lumens206, 208, and 210 so that oil received by the plurality of lumens 206,208, and 210 may exit the outer tube 202 through the plurality of outeroil holes 216, 218, and 220. When an engine component such as one of theplurality of rocker arms 134 of the engine system 100 is attached to therocker shaft 200, the oil of the rocker shaft 200 may exit the rockershaft 200 through the plurality of outer oil holes 216, 218, and 220 andenter an engine component such as the rocker arm 134.

When at least one of the plurality of lumens 206, 208, and 210 is formedin the insert 204, the insert 204 defines a plurality of inner oil holes217 and 219 formed therein, allowing the oil from the at least one ofthe plurality of lumens 206, 208, and 210 formed in the insert 204 toexit the insert 204, as shown in FIG. 4 by the first lumen 206 and theinner oil holes 217 and 219. In some embodiments and as shown in FIG. 4, the number of inner oil holes 217 and 219 may differ from the numberof outer oil holes 216, 218, and 220. In alternative arrangements, thenumber of inner oil holes 217 and 219 may be the same as the number ofouter oil holes 216, 218, and 220. As shown in FIG. 4 , the plurality ofinner oil holes 217 and 219 are positioned along the insert 204 at axiallocations of the rocker shaft 200 that align with the positioning of atleast some of the plurality of outer oil holes 216, 218, and 220 alongthe outer tube 202.

In some embodiments and as shown in FIGS. 3-4 , each of the plurality ofouter oil holes 216, 218, and 220 and each of the plurality of inner oilholes 217 and 219 have a circular shape. In alternative arrangements, atleast one of the plurality of outer oil holes 216, 218, and 220 and/orat least one of the plurality of inner oil holes 217 and 219 may have ashape that is a circle, a circular segment, a circular sector, an oval,a polygon, rounded polygon, or other geometric shape. In someembodiments, each of the plurality of outer oil holes 216, 218, and 220and each of the plurality of inner oil holes 217 and 219 may have thesame shape. In other embodiments, at least one of the plurality of outeroil holes 216, 218, and 220 may have a shape that is different from thatof another of the plurality of outer oil holes 216, 218, and 220, and/orat least one of the plurality of inner oil holes 217 and 219 may have ashape that is different from that of another of the plurality of inneroil holes 217 and 219. In some example implementations, each of theplurality of outer oil holes 216, 218, and 220 and each of the pluralityof inner oil holes 217 and 219 may have a width (e.g., a diameter wherethe shape is circular) that is approximately in a range of 2-15 mm. Atleast one of the plurality of outer oil holes 216, 218, and 220 may havea width that is different from that of another of the plurality of outeroil holes 216, 218, and 220, and/or at least one of the plurality ofinner oil holes 217 and 219 may have a width that is different from thatof another of the plurality of inner oil holes 217 and 219. In someembodiments, each of the plurality of outer oil holes 216, 218, and 220and each of the plurality of inner oil holes 217 and 219 have a widththat is constant. In other embodiments, at least one of the plurality ofouter oil holes 216, 218, and 220 may have a width that varies over thepathway defined by the hole in the outer tube 202, and/or at least oneof the plurality of inner oil holes 217 and 219 may have a width thatvaries over the pathway defined by the hole in the insert 204.

In some embodiments and as shown in FIGS. 3-4 , the plurality of outeroil holes 216, 218, and 220 are positioned along the outer tube 202 withequal spacing between each of the plurality of outer oil holes 216, 218,and 200, and the plurality of inner oil holes 217 and 219 are positionedalong the insert 204 with equal spacing between each of the plurality ofinner oil holes 217 and 219. In alternative arrangements, the pluralityof outer oil holes 216, 218, and 220 may be positioned along the outertube 202 with different spacing between at least some of the pluralityof outer oil holes 216, 218, and 220, and/or the plurality of inner oilholes 217 and 219 may be positioned along the insert 204 with differentspacing between at least some of the plurality of inner oil holes 217and 219. In some embodiments and as shown in FIGS. 3-4 , the pluralityof outer oil holes 216, 218, and 220 are positioned linearly along theouter tube 202 and the plurality of inner oil holes 217 and 219 arepositioned linearly along the insert 204. In alternative arrangements,at least one of the plurality of outer oil holes 216, 218, and 220 maybe positioned at a different radial position of the outer tube 202 thanis another of the plurality of outer oil holes 216, 218, and 220 suchthat the plurality of outer oil holes 216, 218, and 220 are notpositioned in a line along the outer tube 202, and/or at least one ofthe plurality of inner oil holes 217 and 219 may be positioned at adifferent radial position of the insert 204 than is another of theplurality of inner oil holes 217 and 219 such that the plurality ofinner oil holes 217 and 219 are not positioned in a line along theinsert 204.

In some embodiments, an end of the rocker shaft 200 may have a cap (notshown) to block the flow of oil out of the end of the rocker shaft 200.When the insert 204 is manufactured using injection molding, sintering,die cast, investment cast, or additive manufacturing techniques, the capmay be formed as a part of the insert 204. When the insert 204 ismanufactured using an extrusion technique, the cap may be a separatepart from the insert 204.

In some embodiments, the outer tube 202 defines a plurality of outerfastener holes 214 (e.g., opening, gap, etc.) formed therein, and theinsert 204 defines a plurality of inner fastener holes 215 (e.g.,opening, gap, etc.) formed therein. Each of the plurality of outerfastener holes 214 and each of the plurality of inner fastener holes 215are configured to receive a fastener 132 for securing the rocker shaft200 to an engine component such as the overhead structure 130. When thefastener 132 passes through at least one of the plurality of lumens 206,208, and 210, the at least one of the plurality of lumens 206, 208, and210 is wider than the fastener 132 such that the oil in the at least oneof the plurality of lumens 206, 208, and 210 may pass around thefastener 132, as shown in FIGS. 3-4 by the second lumen 208. In someembodiments and as shown in FIGS. 2-4 , the plurality of outer fastenerholes 214 are positioned along the outer tube 202 with equal spacingbetween each of the plurality of outer fastener holes 214 and theplurality of inner fastener holes 215 are positioned along the insert204 with equal spacing between each of the plurality of inner fastenerholes 215. In alternative arrangements, the plurality of outer fastenerholes 214 may be positioned along the outer tube 202 with differentspacing between at least some of the plurality of outer fastener holes214, and/or the plurality of inner fastener holes 215 may be positionedalong the insert 204 with different spacing between at least some of theplurality of inner fastener holes 215.

In some embodiments and as shown in FIGS. 3-4 , each of the plurality ofouter fastener holes 214 and each of the plurality of inner fastenerholes 215 have a circular shape. In alternative arrangements, at leastone of the plurality of outer fastener holes 214 and/or at least one ofthe plurality of inner fastener holes 215 may have a shape that is acircle, a circular segment, a circular sector, an oval, a polygon,rounded polygon, or other geometric shape. In some embodiments, each ofthe plurality of outer fastener holes 214 and each of the plurality ofinner fastener holes 215 may have the same shape. In other embodiments,at least one of the plurality of outer fastener holes 214 may have ashape that is different from that of another of the plurality of outerfastener holes 214, and/or at least one of the plurality of innerfastener holes 215 may have a shape that is different from that ofanother of the plurality of inner fastener holes 215. In some exampleimplementations, each of the plurality of outer fastener holes 214 andeach of the plurality of inner fastener holes 215 may have a width(e.g., a diameter where the shape is circular) that is approximately ina range of 7-24 mm. In some embodiments, each of the plurality of outerfastener holes 214 and each of the plurality of inner fastener holes 215has the same width. In other embodiments, at least one of the pluralityof outer fastener holes 214 may have a width that is different from thatof another of the plurality of outer fastener holes 214, and/or at leastone of the plurality of inner fastener holes 215 may have a width thatis different from that of another of the plurality of inner fastenerholes 215.

In some embodiments, a plug 222 may be positioned in at least one of theplurality of lumens 206, 208, and 210. In some embodiments and as shownin FIG. 4 , the plug 222 is a ball. In alternative arrangements, theplug 222 may have a shape that is a cylindrical plug, cup plug, or othergeometric shape. The plug 222 may have a width equal to the width of theat least one of the plurality of lumens 206, 208, and 210 that the plug222 is positioned in. In some example implementations, the plug 222 maycomprise steel. In FIG. 4 , the plug 222 is positioned in the firstlumen 206. The plug 222 is configured to allow separate oil signalpulses to be provided to a portion of the rocker shaft 200 correspondingto individual cylinders 112 using the one of the plurality of lumens206, 208, and 210 that the plug 222 is positioned in. The oil signalpulses may be used for cylinder deactivation (CDA), variable valvetiming, or variable valve lift, among other variable valve actuationoperations. In CDA, at least one of the cylinders 112 of the enginesystem 100 is not operated (e.g., is deactivated) while at least anotherof the cylinders 112 of the engine system 100 does operate (e.g., isactivated). The cylinder 112 may be configured to be deactivated whenone of the plurality of rocker arms 134, which is configured to move thevalve head 122 above the cylinder 112, receives oil from the rockershaft 200, and may be configured to be activated when the respectiverocker arm 134 does not receive oil from the rocker shaft 200. The plug222 may be positioned in the at least one of the plurality of lumens206, 208, and 210 such that when the at least one of the plurality oflumens 206, 208, and 210 receives oil, that a chosen number of rockerarms 134 may receive oil and a chosen number of rocker arms 134 do notreceive oil, resulting in a chosen number of cylinders 112 beingdeactivated and a chosen number of cylinders 112 remaining activated.When the insert 204 is manufactured using an injection molding,sintering, die cast, investment cast, or additive manufacturingtechnique, a portion of the insert 204, instead of or in addition to aplug 222, may be formed to prevent oil flow to a portion of the rockershaft 200 and may be used for CDA in the same way as the plug 222.

FIG. 5 depicts a flowchart of a method 300 (e.g., process, procedure,etc.) for manufacturing a rocker shaft 200 for oiling engine components.The rocker shaft 200 may be used in an engine system such as the enginesystem 100.

The method 300 includes at 302 providing an outer tube 202 and an insert204. The insert 204 may be manufactured using extrusion, injectionmolding, sintering, die cast, investment cast, or additive manufacturingtechniques. At 304, the insert 204 is placed in the outer tube 202, forexample in a press fit arrangement. At 306, each of a plurality oflumens 206, 208, and 210 defined by the insert 204 and extending throughthe insert 204 are aligned with a plurality of outer oil holes 216, 218,and 220 defined by the outer tube 202. Each of the plurality of lumens206, 208, and 210 are configured to receive oil from an oil pump. Eachof the plurality of outer oil holes 216, 218, and 220 allow the oil fromthe plurality of lumens 206, 208. and 210 to exit the outer tube 202.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of what may beclaimed but rather as descriptions of features specific to particularimplementations. Certain features described in this specification in thecontext of separate implementations can also be implemented incombination in a single implementation. Conversely, various featuresdescribed in the context of a single implementation can also beimplemented in multiple implementations separately or in any suitablesubcombination. Moreover, although features may be described as actingin certain combinations and even initially claimed as such, one or morefeatures from a claimed combination can, in some cases, be excised fromthe combination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

As utilized herein, the terms “substantially,” “generally,”“approximately,” and similar terms are intended to have a broad meaningin harmony with the common and accepted usage by those of ordinary skillin the art to which the subject matter of this disclosure pertains. Itshould be understood by those of skill in the art who review thisdisclosure that these terms are intended to allow a description ofcertain features described and claimed without restricting the scope ofthese features to the precise numerical ranges provided. Accordingly,these terms should be interpreted as indicating that insubstantial orinconsequential modifications or alterations of the subject matterdescribed and claimed are considered to be within the scope of theappended claims.

The term “coupled” and the like, as used herein, mean the joining of twocomponents directly or indirectly to one another. Such joining may bestationary (e.g., permanent) or moveable (e.g., removable orreleasable). Such joining may be achieved with the two components or thetwo components and any additional intermediate components beingintegrally formed as a single unitary body with one another, with thetwo components, or with the two components and any additionalintermediate components being attached to one another.

It is important to note that the construction and arrangement of thevarious systems shown in the various example implementations isillustrative only and not restrictive in character. All changes andmodifications that come within the spirit and/or scope of the describedimplementations are desired to be protected. It should be understoodthat some features may not be necessary, and implementations lacking thevarious features may be contemplated as within the scope of thedisclosure, the scope being defined by the claims that follow. When thelanguage “a portion” is used, the item can include a portion and/or theentire item unless specifically stated to the contrary.

References herein to the positions of elements (e.g., “top,” “bottom,”“above,” “below.” “left.” “right”) are merely used to describe theorientation of various elements in the FIGURES. It should be noted thatthe orientation of various elements may differ according to otherexample embodiments, and that such variations are intended to beencompassed by the present disclosure.

Also, the term “or” is used, in the context of a list of elements, inits inclusive sense (and not in its exclusive sense) so that when usedto connect a list of elements, the term “or” means one, some, or all ofthe elements in the list. Conjunctive language such as the phrase “atleast one of X, Y, and Z,” unless specifically stated otherwise, isotherwise understood with the context as used in general to convey thatan item, term, etc. may be either X, Y, Z, X and Y, X and Z, Y and Z, orX, Y, and Z (i.e., any combination of X, Y, and Z). Thus, suchconjunctive language is not generally intended to imply that certainembodiments require at least one of X, at least one of Y, and at leastone of Z to each be present, unless otherwise indicated.

1. A rocker shaft for oiling engine components, comprising: an outertube defining a plurality of outer fastener openings formed therein; aninsert extending through the outer tube, the insert defining: aplurality of inner fastener openings formed therein, the plurality ofouter fastener openings and the plurality of inner fastener openingsconfigured to receive a fastener for securing the rocker shaft to anengine component; and a plurality of lumens formed therein, each of theplurality of lumens extending through the insert, each of the pluralityof lumens configured to receive oil from an oil pump.
 2. The rockershaft of claim 1, wherein the outer tube defines a plurality of outeroil holes formed therein, the plurality of outer oil holes allowing theoil from the plurality of lumens to exit the outer tube.
 3. The rockershaft of claim 1, wherein the insert comprises a material selected fromthe group consisting of aluminum, steel, ceramic, a polyamide, apolymer, and a polymer composite.
 4. The rocker shaft of claim 1,wherein at least one of the plurality of lumens is formed between theinsert and the outer tube.
 5. The rocker shaft of claim 1, wherein atleast one of the plurality of lumens is formed in the insert.
 6. Therocker shaft of claim 5, wherein the insert defines a plurality of inneroil holes formed therein, the plurality of inner oil holes allowing theoil from the at least one of the plurality of lumens formed in theinsert to exit the insert, and the outer tube defines a plurality ofouter oil holes formed therein, the plurality of outer oil holesallowing the oil from the plurality of lumens to exit the outer tube. 7.The rocker shaft of claim 1, wherein each of the plurality of lumens hasa same cross-sectional shape.
 8. The rocker shaft of claim 1, wherein atleast one of the plurality of lumens has a cross-sectional shapedifferent from that of at least another of the plurality of lumens. 9.The rocker shaft of claim 1, wherein at least one of the plurality oflumens extends through the length of the outer tube.
 10. The rockershaft of claim 1, wherein the outer tube defines an outer recessedgroove formed therein and the insert defines an inner recessed grooveformed therein, the outer recessed groove and the inner recessed grooveallowing the rocker shaft to be attached to an engine component. 11.(canceled)
 12. The rocker shaft of claim 1, further comprising a plugpositioned in at least one of the plurality of lumens, the plugconfigured to allow separate oil signal pulses to a portion of therocker shaft for variable valve actuation.
 13. An engine system,comprising: a cylinder block; a cylinder head connected to the cylinderblock; an overhead structure connected to the cylinder head such thatthe cylinder head is positioned between the cylinder block and theoverhead structure; and a rocker shaft connected to the overheadstructure such that a first end of a rocker arm connected to the rockershaft is positioned above a cylinder of the cylinder block, the rockershaft comprising: an outer tube defining a plurality of outer fasteneropenings formed therein; and an insert extending through the outer tube,the insert defining: a plurality of inner fastener openings formedtherein, the plurality of outer fastener openings and the plurality ofinner fastener openings configured to receive a fastener for securingthe rocker shaft to the overhead structure; a plurality of lumens formedtherein, each of the plurality of lumens extending through the insert,each of the plurality of lumens configured to receive oil from an oilpump.
 14. The engine system of claim 13, wherein the outer tube definesa plurality of outer oil holes formed therein, the plurality of outeroil holes allowing the oil from the plurality of lumens to exit theouter tube.
 15. The engine system of claim 13, wherein the insertcomprises a material selected from the group consisting of aluminum,steel, ceramic, a polyamide, a polymer, and a polymer composite.
 16. Theengine system of any of claim 13, wherein at least one of the pluralityof lumens is formed between the insert and the outer tube.
 17. Theengine system of any of claim 13, wherein at least one of the pluralityof lumens is formed in the insert.
 18. The engine system of claim 17,wherein the insert defines a plurality of inner oil holes formedtherein, the plurality of inner oil holes allowing the oil from the atleast one of the plurality of lumens formed in the insert to exit theinsert, and the outer tube defines a plurality of outer oil holes formedtherein, the plurality of outer oil holes allowing the oil from theplurality of lumens to exit the outer tube.
 19. The engine system of anyof claim 13, wherein each of the plurality of lumens has a samecross-sectional shape.
 20. The engine system of any of claim 13, whereinat least one of the plurality of lumens has a cross-sectional shapedifferent from that of at least another of the plurality of lumens. 21.The engine system of any of claim 13, wherein at least one of theplurality of lumens extends through the length of the outer tube. 22.The engine system of claim 13, wherein the outer tube defines an outerrecessed groove formed therein and the insert defines an inner recessedgroove formed therein, the outer recessed groove and the inner recessedgroove allowing the rocker shaft to be attached to the overheadstructure.
 23. (canceled)
 24. The engine system of claim 23, furthercomprising a plug positioned in at least one of the plurality of lumens,the plug configured to allow separate oil signal pulses to a portion ofthe rocker shaft for variable valve actuation.
 25. A method ofmanufacturing a rocker shaft for oiling engine components, the methodcomprising: providing an outer tube defining a plurality of outerfastener openings formed therein, and an insert defining a plurality ofinner fastener openings formed therein; placing the insert in the outertube; aligning the outer tube with the insert so that (i) each of aplurality of lumens defined by the insert and extending through theinsert are aligned with a plurality of outer oil holes defined by theouter tube, and (ii) the plurality of outer fastener openings arealigned with the plurality of inner fastener openings.
 26. The method ofclaim 25, wherein the step of placing the insert in the outer tubecomprises using press fit to place the insert in the outer tube.
 27. Themethod of claim 25, wherein each of the plurality of lumens isconfigured to receive oil from an oil pump and each of the plurality ofouter oil holes allows the oil from the plurality of lumens to exit theouter tube.
 28. The rocker shaft of claim 1, wherein a width of at leastone lumen of the plurality of lumens normal to a flow directiontherethrough is greater than a width of at least one of the plurality ofinner fastener openings.
 29. The rocker shaft of claim 1, wherein atleast one of the plurality of lumens defines a pathway have at least onebend proximate to at least one of the plurality of inner fasteneropenings.